The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results?

• A. It is important to use a gene that has been affected by natural selection to ensure that evolution will be observed.
• B. It is important to use one gene in which the changes are clearly neutral.
• C. It is best to use a gene that is essential to survival because they change more slowly.
• D. All of the listed responses are correct.
• E. It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out.